Neural crest
A band of cells along the border where the neural tube pinches off from the ectoderm; the
cells migrate to various parts of the embryo and form the pigment cells in the skin, bones of
the skull, the teeth, the adrenal glands, and parts of the peripheral nervous system.
Neural groove
Dorsal, longitudinal groove that forms in a vertebrate embryo; bordered by two neural
folds; preceded by the neural-plate stage and followed by the neural-tube stage.
Neural plate
Thickened strip of ectoderm in early vertebrate embryos that forms along the dorsal side of
the body and gives rise to the central nervous system.
Neural tube
Primitive, hollow, dorsal nervous system of the early vertebrate embryo; formed by fusion
of neural folds around the neural groove.
Neuromodulator
A chemical agent that is released by a neuron and diffuses through a local region of the
central nervous system, acting on neurons within that region; generally has the effect of
modulating the response to neurotransmitters.
Neuromuscular junction
The junction between an axon terminal of a motor neuron and a muscle fiber innervated by
that motor neuron; the axon terminal of a motor neuron is typically branched, forming
neuromuscular junctions with a number of different muscle fibers.
Neuron
A nerve cell; the fundamental unit of the nervous system, having structure and properties
that allow it to conduct signals by taking advantage of the electrical charge across its cell
membrane.
Neurosecretory cells
Hypothalamus cells that receive signals from other nerve cells, but instead of signaling to an
adjacent nerve cell or muscle, they release hormones into the bloodstream.
Neurotransmitter
A chemical messenger released from the synaptic terminal of a neuron at a chemical
synapse that diffuses across the synaptic cleft and binds to and stimulates the postsynaptic
cell.
ff
(ff)
#1